<!DOCTYPE html>
<html lang="en">
<head>
	<meta charset="UTF-8">
	<meta http-equiv="X-UA-Compatible" content="IE=edge">
	<meta name="viewport" content="width=device-width, initial-scale=1.0">
	<title>Document</title>
</head>
<body>
	<select name="" id="">
		<!--  option的value会同步给select下拉列表 
			  这个值是可读可写的   
					读  document.querySelector('select').value
					写  document.querySelector('select').value = '2'
		
		-->
		<option value="1">北京</option>
		<option value="2">上海</option>
		<option value="3">广州</option>
		<option value="4">深圳</option>
	</select>
</body>
</html>